Testing equipment: The illuminance meter used for the illuminance test must be suitable for a floodlit environment, with a wide angle receptive light sensor. The meter must be recalibrated annually.
Test procedure: The field of play is divided up into a grid containing 96 points. At each point, an illuminance test is carried out to measure both the horizontal illuminance (at one angle) and the vertical illuminance (at four different angles). Thus, the test procedure requires 480 illuminance tests in total. The illuminance meter must always be positioned at the correct angle for the intended measurement. Personnel carrying out the test must not create any shadows that could influence the readings. The meter must be 1m above the playing surface. The illuminance reading for each grid point must be recorded on the relevant illuminance grid plan.
Horizontal test: The meter is positioned facing upwards, 1m above the playing surface, and parallel to the pitch, at every grid point.
Vertical test: The meter is positioned perpendicular to the pitch, 1m above the playing surface, at every grid point. The meter must then be adjusted for each of the four test positions. The test positions are indicated on the vertical illuminance grid plan and are at 0°, 90°, 180° and 270°. This procedure must be repeated at all 96 grid points.
Uniformity ratios are calculated as follows:
U1: E min/E max
U2: E min/E med